Turbulence PIREPs in Juneau– An Analysis

Flights into and out of the Alaskan capitol of Juneau are an important part of the economic and political structure of Alaska. Juneau is only accessible by plane or boat making the safety of these routes very important to both the people of Juneau as well as the state of Alaska. Turbulence encounters on the approach and departure paths of the Juneau airport have impacted both safety and flight capacity. The Research Applications Program (RAP) of the National Center for Atmospheric Research (NCAR) has been primarily responsible for the development of a turbulence detection system in the Juneau area. The Juneau Wind Hazard Alert System (JWHAS) estimates turbulence hazards using information from a variety of anemometers and wind profilers placed near the approach and departure paths of the Juneau airport. As part of the development of this system, two research aircraft collected turbulence and wind shear measurements during a field project. The pilots gave voice pilots’ reports (PIREPs) of turbulence during their flights. The project lasted from October 5, 2002 until January 19, 2003 and a total of 49 flights included PIREPs. The analyses presented in this paper will summarize the information obtained from these PIREPs. Case study analysis of two severe turbulence encounters will also be presented.